Introduce the transport-helper capability 'stateless-connect'. This
capability indicates that the transport-helper can be requested to run
the 'stateless-connect' command which should attempt to make a
stateless connection with a remote end. Once established, the
connection can be used by the git client to communicate with
the remote end natively in a stateless-rpc manner as supported by
protocol v2. This means that the client must send everything the server
needs in a single request as the client must not assume any
state-storing on the part of the server or transport.
If a stateless connection cannot be established then the remote-helper
will respond in the same manner as the 'connect' command indicating that
the client should fallback to using the dumb remote-helper commands.
A future patch will implement the 'stateless-connect' capability in our
http remote-helper (remote-curl) so that protocol v2 can be used using
the http transport.
Signed-off-by: Brandon Williams <bmwill@xxxxxxxxxx>
---
Documentation/gitremote-helpers.txt | 32 +++++++++++++++++++++++++++++
transport-helper.c | 11 ++++++++++
transport.c | 1 +
transport.h | 6 ++++++
4 files changed, 50 insertions(+)
diff --git a/Documentation/gitremote-helpers.txt b/Documentation/gitremote-helpers.txt
index 4a584f3c5..a8361ed95 100644
--- a/Documentation/gitremote-helpers.txt
+++ b/Documentation/gitremote-helpers.txt
@@ -102,6 +102,14 @@ Capabilities for Pushing
+
Supported commands: 'connect'.
+'stateless-connect'::
+ Experimental; for internal use only.
+ Can attempt to connect to a remote server for communication
+ using git's wire-protocol version 2. This establishes a
+ stateless, half-duplex connection.
++
+Supported commands: 'stateless-connect'.
+
'push'::
Can discover remote refs and push local commits and the
history leading up to them to new or existing remote refs.
@@ -136,6 +144,14 @@ Capabilities for Fetching
+
Supported commands: 'connect'.
+'stateless-connect'::
+ Experimental; for internal use only.
+ Can attempt to connect to a remote server for communication
+ using git's wire-protocol version 2. This establishes a
+ stateless, half-duplex connection.
++
+Supported commands: 'stateless-connect'.
+
'fetch'::
Can discover remote refs and transfer objects reachable from
them to the local object store.
@@ -375,6 +391,22 @@ Supported if the helper has the "export" capability.
+
Supported if the helper has the "connect" capability.
+'stateless-connect' <service>::
+ Experimental; for internal use only.
+ Connects to the given remote service for communication using
+ git's wire-protocol version 2. This establishes a stateless,
+ half-duplex connection. Valid replies to this command are empty
+ line (connection established), 'fallback' (no smart transport
+ support, fall back to dumb transports) and just exiting with
+ error message printed (can't connect, don't bother trying to
+ fall back). After line feed terminating the positive (empty)
+ response, the output of the service starts. Messages (both
+ request and response) must be terminated with a single flush
+ packet, allowing the remote helper to properly act as a proxy.
+ After the connection ends, the remote helper exits.
++
+Supported if the helper has the "stateless-connect" capability.
+
If a fatal error occurs, the program writes the error message to
stderr and exits. The caller should expect that a suitable error
message has been printed if the child closes the connection without
diff --git a/transport-helper.c b/transport-helper.c
index c032a2a87..e20a5076e 100644
--- a/transport-helper.c
+++ b/transport-helper.c
@@ -12,6 +12,7 @@
#include "argv-array.h"
#include "refs.h"
#include "transport-internal.h"
+#include "protocol.h"
static int debug;
@@ -26,6 +27,7 @@ struct helper_data {
option : 1,
push : 1,
connect : 1,
+ stateless_connect : 1,
signed_tags : 1,
check_connectivity : 1,
no_disconnect_req : 1,
@@ -188,6 +190,8 @@ static struct child_process *get_helper(struct transport *transport)
refspecs[refspec_nr++] = xstrdup(arg);
} else if (!strcmp(capname, "connect")) {
data->connect = 1;
+ } else if (!strcmp(capname, "stateless-connect")) {
+ data->stateless_connect = 1;
} else if (!strcmp(capname, "signed-tags")) {
data->signed_tags = 1;
} else if (skip_prefix(capname, "export-marks ", &arg)) {
@@ -612,6 +616,13 @@ static int process_connect_service(struct transport *transport,
if (data->connect) {
strbuf_addf(&cmdbuf, "connect %s\n", name);
ret = run_connect(transport, &cmdbuf);
+ } else if (data->stateless_connect &&
+ (get_protocol_version_config() == protocol_v2) &&
+ !strcmp("git-upload-pack", name)) {
+ strbuf_addf(&cmdbuf, "stateless-connect %s\n", name);
+ ret = run_connect(transport, &cmdbuf);
+ if (ret)
+ transport->stateless_rpc = 1;
}
strbuf_release(&cmdbuf);
diff --git a/transport.c b/transport.c
index 8e38352c5..2e7b7a715 100644
--- a/transport.c
+++ b/transport.c
@@ -250,6 +250,7 @@ static int fetch_refs_via_pack(struct transport *transport,
data->options.check_self_contained_and_connected;
args.cloning = transport->cloning;
args.update_shallow = data->options.update_shallow;
+ args.stateless_rpc = transport->stateless_rpc;
if (!data->got_remote_heads)
refs_tmp = get_refs_via_connect(transport, 0, NULL);
diff --git a/transport.h b/transport.h
index daea4770c..0ef0d1902 100644
--- a/transport.h
+++ b/transport.h
@@ -55,6 +55,12 @@ struct transport {
*/
unsigned cloning : 1;
+ /*
+ * Indicates that the transport is connected via a half-duplex
+ * connection and should operate in stateless-rpc mode.
+ */
+ unsigned stateless_rpc : 1;
+
/*
* These strings will be passed to the {pre, post}-receive hook,
* on the remote side, if both sides support the push options capability.
--
2.16.2.395.g2e18187dfd-goog
